Malicious PDF — malware analysis report

Static analysis result for SHA-256 7d95a43caf79c2b8…

MALICIOUS

PDF

68.6 KB Created: 2021-10-03 18:12:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: a6103f8daa891a7cceee78b27ff66be7 SHA-1: 3a33c5c91be5b9750e49273e32ce976c87e60c84 SHA-256: 7d95a43caf79c2b8ddbc29058be0c3ad01e3bbe8121dc17c977d9ec9162f12fb
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm on disposable hosting. The PDF contains numerous embedded URLs pointing to external PDF files, suggesting a multi-stage download or redirection mechanism. While no scripts were explicitly extracted, the nature of the embedded URLs and the link farm heuristic strongly suggest an intent to redirect users to malicious content, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://greenworx.eu/images/uploads/files/5142393142.pdf In PDF document text
    • http://stylekd.ru/files/68548837248.pdfIn PDF document text
    • http://ain.proximeo.com/ckfinder/userfiles/files/nuwabajudaxox.pdfIn PDF document text
    • http://everintelconsulting.com/upload/file/202109060544259661.pdfIn PDF document text
    • http://xn--9w3b270a7kf.kr/data/editor/file/dijuw.pdfIn PDF document text
    • http://upoart.com/ckfinder/userfiles/files/22494903503.pdfIn PDF document text
    • http://go-pxl.com/uploads/files/zodamotilebixudigumoruf.pdfIn PDF document text
    • https://mimpi1pusat.com/contents/files/rupamozo.pdfIn PDF document text
    • http://talentfuturesservices.com/sharpinstitute/images/files/kulekosalobobaveropek.pdfIn PDF document text
    • http://medrea.ru/upload/files/64858595025.pdfIn PDF document text
    • https://amagi.la/wp-content/plugins/formcraft/file-upload/server/content/files/161304b3db0d37---48530367386.pdfIn PDF document text
    • http://zhengfutz.com/v15/Upload/file/2021103821413043.pdfIn PDF document text
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136a862ed397---divali.pdfIn PDF document text
    • http://autoklej.pl/app/webroot/media/files/woziritamin.pdfIn PDF document text
    • https://clubslotalmatriche.com/calcas/file/fejiri.pdfIn PDF document text
    • http://em-ail.ch/pictures/2/dajedamil.pdfIn PDF document text
    • http://luisacortesearchitetto.it/userfiles/files/12491912952.pdfIn PDF document text
    • http://espicycooking.com/files/file///farilosinesewetigakin.pdfIn PDF document text
    • http://konberdbio.com/upload/files/75705671179.pdfIn PDF document text
    • https://giltmorestukko.hu/ckfinder/userfiles/files/gilopagumibatusojuwepe.pdfIn PDF document text
    • https://globalcircle.club/userfiles/file/69390402715.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=pharmacy+alligation+practice+problemsPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ae4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE4C 11076 bytes
SHA-256: e81d141b44d5ab004eefc1516546b6cdd7cfb70a0992ec1c91d1a8febcd0764c
font_01_sfnt_off0000c7bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC7BF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000dfd1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFD1 14644 bytes
SHA-256: 04eed46a94e9d65ff4e2ae3a7fc0eaa91d8099ed55b1242dd9c9a983f4ab8bbb